Mechanical-electrical sound reproducer



Fan, 23, 1945. ca. couRcY ETAL Y 2,363,003

MECHANICAL-ELECTRICAL SOUND REPRODUCER Filed Aug. 14, 1942 v v A; "nu mu 1 In ven ior GEORGES COl/PCV MARCEL HQUL OUR/IND y W 4i Torn 6y.

Patented Jan. 23, 1945 MECHANICAL-ELECTRICAL SOUND nsrnonucnn Georges Courcy, Le Pec rand, St.-Germain en ti, and Marcel Paul Due Laye, France; vested in the Alien Property Custodian Application August 14, 1942, Serial No. 454,870 r/ In France October 24, 1941 3 Claims. (01.179-10041) The invention relates to a mechanical-electrical sound-reproducer for phonographs.

-..pick-up") the r gards weight and fragility, are known, and the For said machines use is generally made of magnet or crystal sound reproducers (known as disadvantage of which, as resound-giving efllciency oi whichbecomes weaker with use.

Said disadvantages are avoided in the sound reproducer which forms the subject matter of the invention which is essentially characterised by the fact that the vibrations of its needle (or sapphire point) act, through the moving component which supports it, on one or more'charges of dust or grain of carbon-or on'some other similar conducting substance-each of which is secured within an elastic,'supple and insulating housing and subject to a pressure which is separately adjustable for eachsingle one of them, each charge being traversed by an exciting which is thus modulated by the vibrations of the moving component, which exciting current may be provided by a'cell, an accumulator or rectified current while the modulated current may then be transformed so as to be sent to the amplifier.

It is therefore the mechanical vibrations of the needle or of the sapphire point caused by its friction in the grooves registered on the disk or cylinder of the talking machin which are here directly utilized for the purpose of acting on the potential modifier or modifiers which are conabout knife-edges: Figure 2 stituted by the charge or charges of granulated carbon but said charges are immobilized by a pressure which is sufllcient to prevent any friction of the grains against oneanother or against the surfaces with which they are in contact, thus avoiding the parasitic noises which might be set up by such friction.

It will be readily understood that the trepida- I tions of the apparatus as a whole thus-have no effect on sound production and that the sound is modulated solely by .the vibrations of themoving component. a

The attached figure shows non-restrictiveexamples of forms of embodiment of the invention.

. Figure 1 is a sectional view of a reproducer the moving component of which is constituted by a diaphragm or blade capable of flexing. Figures 2 to 4 are views of reproducers in which the movcomponent, which is itself rigid, is articulated is an embodiment including onlyone charge of carbon, Figure 3 is an embodiment withtwo opposedgcharges, Figure' 4 is an embodiment with four opposed and balanced charges. Figure 5 is a variant of Figcurrent rendered solid with ure 4 in which the moving component is not articulated about knife-edges but merely held by the supple substance inwhich the carbon charges are embedded. v

In said figures the same numerals indicate the same components: I and 2 are the two portions of the housing made of an insulating substance assembled by bolts 3; 5 is the needle which is moving component 6 by means of binding screw 1; 8 are sleeves made of flexible substance (such as rubber, gelatin, etc.)

interposed between the housing and th moving component and preferably glued to said components to constitute cavities accommodating the charges 9 of granulated carbon or of some other similar conducting, substance on each of which the pressure can be adjusted by a cap it) screwed way departing from into the housing.

In the examplei Figure 1 the moving component is constitu by. a flexible blade or diaphragm squeezed between the two portions of the housing; in Figures 2 to 4 th moving component is solid and articulated about knife-edges and I2 which are integral withthe two portions of the housing; in Figure 5 the solid movin component is held by the-supple or yielding substance which constitutes sleeves 8, which substance may with advantage be extended to a greater surface in order to increase the holding of the moving component in relation to. the housing.

Th current to be modulated is led, on the one hand, to the moving component by wire 13 and, on the other hand, by wire l4 to cap in which is assumed to be conducting, both said components thus being in contact by means of the carbon charge Swhich forms a resistance. In the case 'of Figure 3. a third wire it connects the second cap Hi to a compensated mounting .gpu'sh pull). In thecase of Figures 4 and 5, wire i4 leads to two caps l0 diametrically opposed with respect to the centre of oscillation of 6 whereas wire l5 leads to the other two caps I 0.

Thenumber of charges subjected to the action of the same moving component is in nowise limited to those of the examples described herein above and it'- will be readily understood, without it being necessary to represent them, that said arrangements can be multiplied in depth or ,ar-

ranged in a different manner without in any invention as set forth in the following claims.

What we claim is:

1. Ame'c hanlcal electrical sound reproducerfor phonographs comprising a'casing formed of the characteristics of [the I two blocks oi insulating materials secured together and forming between them two openings with inwardly extending V-shaped projections, between the openings, a stylus holder having opposite recesses into which said projections 5 extend to tiltably support the holder and resist- -ance units variable by changes in pressure carried by said blocks in contact with said stylus holder at points removed from said support.

2. The reproducer as set forth in claim 1 where each block carries twounits located at opposite sides 01 said support in said respective openings. 3. The reproducer as set forthin claim 1 wherer in said units each comprises a holding sleeve of yielding material, granular conducting material in said sleeve and a conducting screw in the corresponding block in contact with said material and serving to support said sleeve.

' GEORGES COURCY.

MARCEL PAUL DURAND. 

